Selective impairment in recognizing the familiarity of self faces in schizophrenia

The concept of self is a fundamental characteristic of the human mind, and the alteration of self is thought to be a core deficit of schizophrenia. Previous studies have demonstrated that patients with schizophrenia are deficient in self-face recognition. Because self faces are not only self-related but also highly familiar, it is unclear whether such deficit arises from the breakdown of the self-awareness or the failure of recognizing the familiarity of self faces. Here we directly tested these two alternatives by instructing patients with schizophrenia to recognize the identity of a morphed face created by blending face features between any of two identities from the self face, a familiar face, and a novel face. We found that there was no association between the recognition of the self and the recognition of the familiarity, suggesting these two component processes are independent in schizophrenia. Further, patients with schizophrenia were significantly worse in recognizing the familiarity of faces than normal participants, whereas no difference in the sense of self was found between the two groups. Taken together, our finding suggests that it is the sense of familiarity, not the sense of self, that is selectively impaired in self-face recognition in schizophrenia. Thus, our study challenges the hypothesis that the deficit in self-face recognition in schizophrenia reflects the breakdown of self-awareness.